20:[-40, -12, 89, 3, 32, -31, 52, 58, -111, 91, 99, -108, 23, 6, 80, -88, -13, 93, 105, 38]
20:[-40, -12, 89, 3, 32, -31, 52, 58, -111, 91, 99, -108, 23, 6, 80, -88, -13, 93, 105, 38]

16:[27, -62, -101, 54, -10, 35, -70, -126, -86, -10, 114, 79, -45, -79, 103, 24]
16:[27, -62, -101, 54, -10, 35, -70, -126, -86, -10, 114, 79, -45, -79, 103, 24]

[68, 97, 116, 97, 32, 83, 105, 103, 110, 97, 116, 117, 114, 101]
[48, 44, 2, 20, 69, 61, 80, 91, 19, 124, 18, -99, -33, -97, -91, -76, -41, 47, -81, 39, -19, 57, 60, -12, 2, 20, 96, 37, 20, 54, -115, -98, 57, 127, 29, 47, -127, -59, 90, -58, 38, 30, -97, 76, -31, 119]



19050619766489163472469

JCA(Java Cryptography Architecture):Java加密体系结构
	提供证书、数字签名、消息摘要、密钥对生成器
JCE(Java Cryptography Extension):Java加密扩展包
	在JCA的基础上作出扩展，提供了各种加密算法，消息摘要算法和密钥管理，DES、AES、RSA、DSA
	这些算法实现
JSSE(Java Secure Sockets Extension):Java安全套接字扩展包
	基于SSL的加密功能
JAAS(Java Authentication and Authentication Service):Java鉴别与安全服务
	
消息摘要算法分为三类：
	MD(Message Digest):消息摘要
	SHA(Secure Hash Alogrithm):安全散列
	MAC(Message Authentication Code):消息认证码
	
密钥：
	SecuretKey:对称密钥顶层接口
		DES、AES
	PublicKey和PrivateKey：非对称密钥接口
		RSA、DSA、EC
		
java6支持的MD2、MD5、SHA-1、SHA-25、SHA-384、SHA-512六种信息摘要算法